An insulated gate bipolar transistor (hereinafter referred to as “IGBT”) using silicon (Si) or silicon carbide (SiC) as a semiconductor material is known.
In the IGBT, various techniques have been proposed in order to reduce the resistance during the ON state, that is, the on-resistance. For example, in the technique of Patent Document 1, forming a carrier accumulation region for carrier accumulation reduces the on-resistance. In addition, for example, in the technique of Patent Document 2, forming a current suppressing layer reduces the on-resistance.